LIGO Document T1400562-v1

ITM09 Mounting flat fracture

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Document type:
T - Technical notes
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The left hand mounting flat fractured during removal of a sapphire prism for wire hang. This is a collection of the documentation of the fracture and associated relevant files.

The fracture appears to be a clean "clamshell" with no residual fracture lines propagating into the test mass. Analysis indicates that the Suspension ear will lie entirely below the void. The suspension bond starts at 17 mm below the center fiducial. The maximum extent of the clamshell is 15 mm below the center fiducial.

The prisms had been soaking since August 18 in Methylene Chloride as recommended by the vendor. Stress had been applied since August 21 using a spreader between the prisms, there was no damage evident as of the evening of August 25.

Bond thickness measurement was attempted using the Olympus dark field microscope. The results are shown in the file 20x_glueThick.jp2.pdf. The measurement is coarse, the thickness is estimated to be 5 micrometers.

Relevant documents:
D080479 sapphire prism used for wire hang
D080751 Production Ear

Files in Document:
Other Files:
Notes and Changes:
Full time soak on remaining prism began 8-29-14
Related Documents:
Referenced by:

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